Objective       To investigate the expression of RANKL and M-CSF in the synovium of collagen-induced arthritis (CIA) rats and the intervention of T-614 and methotrexate (MTX) on their expression.       Methods       The CIA animal models (

n

=40) were established by injecting type Ⅱ collagen and complete Freud’s adjuvant

and then were divided randomly int

o 4 groups

including a model group (

n

=10)

a MTX group (

n

=10)

a T-614 group and a MTX+T-614 group (

n

=10). Arthritis was evaluated by arthritis index (AI). The expression of RANKL and M-CSF in the synovium was detected by Western blotting. The synovial pathological score of ankle joints

the radiographic changes and synovial thickness were evaluated.       Results       The arthritis index

the expression of RANKL and M-CSF in the synovium

the synovial pathological score

the X-ray score and the synovial thickness were increased in the model control group

the MTX group

the T-614 group and the MTX+T-614 group as compared to the normal control group (

P

<

0.05). Compared with the model control group

all above indices were significantly decreased in the MTX group

the T-614 group and the MTX+T-614 group (

P

<

0.05). Compared with the MTX group and the T-614 group

all above indices were decreased in the MTX+T-614 group (

P

<

0.05).  No difference was found in these indices between the MTX and T-614 groups (

P

>0.05).       Conclusion       RANKL and M-CSF are involved in the occurrence and development of joint synovitis in CIA rats. T-614 and MTX can delay the inflammation and bone/cartilage destruction in joint synovitis by synergistically suppressing the expression of RANKL and M-CSF.